Cryogenic storage apparatus



July 16, 1963 R. J. BERTA ETAL 3,097,900

CRYOGENIC STORAGE APPARATUS Filed May 11, 1961 INVENTORS B T REMO J ER AWILFRIED HAUMANN ATTOR/V V United States Patent i 7 3,097,900 CRYOGENICSTORAGE APPARATUS Remo J. Berta and Wilfried Haumann, Indianapolis, Ind,assignors to Union Carbide Corporation, a corporation of New York FiledMay 11, 1961, Scr. No. 109,443 6 Claims. (Cl. 312-214) This inventionrelates to an apparatus for storing perishable products at lowtemperature and more particularly to an apparatus for driving a conveyorsystem that carries receptacles containing the perishable products.

Prior to this invention, practical low-temperature storage of perishableproducts, such as biological substances, was hindered by the apparatusemployed to store and dispense the perishable products. One type ofprior art container had the driving means for the conveyor apparatuslocated in the central portion of the container and a separate adjacentopening for filling the container with the liquid refrigerant and forinserting and removing the receptacles. This type of device had theserious disadvantage of having an excessive amount of heat leak to thecontainer. Specifically, it was found that in containers having a singlecentral opening, about 60% of the heat leak to the container was throughthe central opening. Obviously to have another opening increased theheat leak in orders of magnitude. Such heat leak substantially reducedthe holding time of the container through excessive loss of refrigerant.

A device that utilizes the driving means in conjunction with a singlecentral container outlet is disclosed in US. application Serial No.26,218, filed May 2, 1960, in the name of W. Haumann, now US. Patent3,034,845. This device was capable of positioning various receptaclesbeneath the container opening thereby simplifying the problem of storagespace accessibility. The container had a centrally-located, elongatedneck tube that extended into the upper region of the storage space. Aplug, when inserted into the opening, engaged the actuating mechanismthat was located about the periphery of the lower end of the neck tube.By rotating this plug, the mechanism was actuated and thereby moved thereceptacles beneath the opening in sequence. Such arrangement had thedisadvantage that the plug had to be removed each time a particularreceptacle was to be placed in its proper position within the containerso that it could be withdrawn from the container, and then reinsertedand rotated to position another receptacle. Not only was this continualremoving and reinserting the plug an inconvenience but it also tended topump atmospheric air into the storage space which brought atmosphericair into contact with the refrigerant thereby creating a fog due to thecondensation of the water vapor in the air. This fog clouded thereceptacles from view.

It is therefore an object of this invention to minimize undesirable heatleak into the storage container by providing an externally operatedreceptacle conveyor driving apparatus positioned within a single accessport.

Another object of this invention is to eliminate undesirable pumpingaction by providing an actuating mechanism that operates independentlyof the container opening plug. These and other objects and advantages ofthe invention will become apparent from the following description andthe accompanying drawings in which:

FIGURE 1 is a vertical elevational view, shown partially incross-section, of a; low-temperature storage container embodying theapparatus of this invention.

FIGURE 2 is a fragmentary view on an enlarged scale of the neck sectionof the container of FIGURE 1, with the access-port plug removed.

According to the invention a receptacle conveyor assembly located withina storage container is actuated from the exterior through the containersaccess port. A suitable conveyor assembly is dcscribed in the previouslymentioned US. application Serial No. 26,218, filed May 2, 1960, in thename of W. Haumann, now US. Patent 3,034,845. It is to be understood,however, that the pres-- 'ent invention is not limited to employmentwith this particular conveying apparatus. The conveyor assemblydescribed therein comprises a rotatable drive member positioned aroundthe lower end of the containers access port which is separated from areceptacle conveying apparatus by several longitudinally positionedsupport rods. A journalled transmission shaft communicates with therotatable drive member at its upper end and with the receptacleconveying apparatus at the shaft lower end. An endless chain, which isattached to the transmission shaft by a rotatable sprocket and comprisesa major part of such conveying apparatus, is directed at one point inits traverse beneath the access port. At uniformly spaced intervalsalong the chain, receptacle holders are attached which are accessiblefrom the exterior when positioned beneath the containers access port atthe aforementioned point along the conveyor chains traverse.

The actuating apparatus of the present invention, hereinafter designatedas a drive tube, communicates with the rotatable drive member throughthe containers access port in a manner such that its operation will notinterfere with the accessibility of the contain-ers interior storagespace. Thus, the actuating apparatus of the present invention need notbe removed from the access port to remove a particular receptacle. Theaccess port of the container is provided with a neck tube, such as isfound in most storage containers of this type. The actuating member ofthe present invention, comprising a tube of slightly smaller diameterthan the above noted neck tube, is capable of being connected to therotatable drive member located around the circumference of the lower endof such smaller diameter tube. The indexing part of the drive tube whichis rigidly attached to the upper end of the tube, fitted within the necktube of the container, is positioned on top of the container. As thedrive tube is rotated, the rotatable drive member is turned therebyactuating the transmission shaft and the conveyor chain.

The particular embodiment of the invention as shown in FIGURES 1 and 2is employed in a double-walled storage container 10 which comprises anouter shell 12, an inner storage vessel 14, which defines an insulatedspace 16 therebetween. The insulated space is preferably evacuated toless than about 25 microns of mercury and filled with an opacifiedinsulation such as is described in copending US. application Serial No.597,947, filed July 16, 1956, in the name of L. C. Matsch, now US.Patent 3,007,596 and US. Patent No. 2,967,150. issued January 3, 1961 toL. C. Matsch et al. The access port 18 of the container is formed byneck tube 20 which is attached at its upper end to outer shell 12 and atits lower end to inner storage vessel 14. The access port 18 ispreferably centrally located as depicted in FIGURE 1.

The receptacle conveyor chain (not shown), positioned in the bottom ofthe storage vessel 14, is actuated by rotating a rotatable drive member22, which latter member is connected to drive transmission shaftsprocket 24 through a chain 26. Member 22 and sprocket 24 are supportedon a support plate 28 which is separated from the conveyor chain bylongitudinal support rods 30. Transmission shaft 32 connects with theconveyor chain at the shaft lower end by means of a sprocket at itslower end, similar to sprocket 24.

The preferred embodiment of the invention as shown in" FIGURE 2,comprises a tube 34 fitted within neck tube 20, the former beingreinforced by upper ring 36 and lower ring 36a. As shown in FIG. 1, adish-shaped disk 38 is integrally attached to tube 34 and togethercomprise the previously mentioned drive tube. An indexing pointer 40 isintegrally attached to the top of container so as to remain fixed withrelation to the rotatable drive tube. Returning to- FIG. 2, pin 42engages L-shaped slot 44 in ring 36a and is integrally attached torotatable drive member 22 such that tube 34 is engaged with thereceptacle conveying apparatus. Container access port plug 46 of FIG. 1,while not shown in FIGURE 2, snugly fits into tube 34.

To engage the conveying apparatus, tab 44a, is first bent back so thatpin 42 of the conveying apparatus can be engaged with L-shaped slot 44.The tab 44a is then bent back to its original position to lock pin 42 inplace.

Tube 34 is preferably constructed from a thermosetting plastic such as aphenolformaldehyde resin reinforced with paper or fabric. Reinforcingrings 36 and 36a may be constructed of stainless steel and may be bondedto tube 34 with a suit-able epoxy resin. Dish-shaped disk 38, if made ofa suitable metal, may be welded to upper support ring 36.

Referring to FIGURE I, plug 46 is constructed of a low heat conductingmaterial such as, for example, one of the various foam plastics, orcorks. The closeness of the fit between the inner wall of tube 34 andplug 46 outer surface, forces the refrigerant vapors to exit to theatmosphere through the annular space 48 defined by the adjacent walls ofthe neck tube 20 and tube 34 rather than through the space between theplug and the tube. Tube 34, in order to be rotatable within neck tube20, must have a slightly smaller diameter. Therefore, space 48 betweentube 34 and neck tube 20 acts as a refrigerant vapor path inasmuch asthis path offers the least resistance to the exiting vapors. Asubstantial portion of the refrigeration of the escaping vapors isthereby recovered because of the extended heat transfer path whichencompasses not only space 48 but also the path between the dish-shapeddisk 38 and the top of the container 10.

The disk 38 is calibrated such that indexing pointer 40 indicates theposition of the conveyor chain within the container. Consequently, anydesired receptacle or receptacle holder which is carried by the conveyorcan be brought into alignment with the containers access port 13 byrotating disk 38 until the proper index marking on disk 38 is alignedwith pointer 40. If a receptacle is to be removed or put into .a holderon the conveyor chain, plug 46 is removed first. If another receptacleis to be removed or placed into position at that time, the conveyor isagain indexed as described above but with the plug removed. When all thereceptacles are removed or placed within the container as are desired atthat time, the plug is reinserted. Thus, the plug need only be removedonce, thereby eliminating excessive pumping action caused by additionalplug movement. Consequently, the heat leak into the container isreduced. Elimination of this pumping aotion also prevents the influx ofmoisture laden air into the container which would cause the formation offog and ice deposits.

Although the preferred embodiment of the invention has been described indetail, it is contemplated that modifications of the apparatus may bemade and that some features may be employed without others, all withinthe spirit and scope of the invention.

What is claimed is:

1. In an apparatus for storing and dispensing low-temperature materialscomprising a double-walled vacuuminsulated storage container having anaccess port in the top wall thereof communicating with the containerinterior, a conveyor means positioned in such interior, transmissionmeans located within said interior and rotatably communicating with saidconveyor means, a rotatable drive member positioned in said interior andoper-ably attached to said transmission means, and a removable lowheatconductive means for closing said access port thereby substantiallycompletely sealing said interior from the effects of ambient heat, theimprovement comprising a rotatable transmission actuating means fittedwithin said access port such that operation of such actuating means doesnot effect the accessibility of said interior; said actuating meanscomprising a tube which is connected to said transmission means by saidrotatable drive member, and a rotatable disk integrally attached to theupper portion of said actuating means such that upon rotating such disk,said actuating means actuates said transmission means thereby operatingsaid conveyor means.

2. In an apparatus for storing and dispensing lowtemperature materialscomprising a double-walled vacuum insulated storage container having anaccess port in the top wall thereof communicating with the containerinterior, a conveyor means positioned in the lower portion of suchinterior, transmission means extending from the upper portion of saidinterior to the lower portion thereof and rotatably communicating withsaid conveyor means through a gearing arrangement, a rotatable drivemember positioned in the upper portion of said interior and operablyattached to the upper portion of said transmission means, and aremovable low-heat conductive means for closing said access port therebysubstantially completely sealing said interior from the effects ofambient heat, the improvement comprising a rotatable transmissionactuating means fitted within said access port such that operation ofsuch actuating means does not effect the accessibility to said interior;said actuating means comprising a tube which is connected to the upperportion of said transmission means by said rotatable drive member, and arotatable disk integrally attached to the upper portion of saidactuating means such that upon rotating such disk, said actuating meansactuates said transmission means thereby operating said conveyor means.

3. Apparatus according to claim 1 wherein said rotatable drive memberincludes a pin and said tube includes a L-shaped slot positioned in thelower portion of such tube, said tube being connected to said rotatabledrive member by said pin which extends into said L- shaped slot.

4. Apparatus according to claim 1 wherein said tube is constructed of athermosetting plastic material which is reinforced by two annularreinforcing rings which are integrally attached to the outer peripheryof said tube, one of said rings near the upper end of such tube and theother near the lower end; and wherein said rotatable annular disk isintegrally attached to the upper reinforcing ring.

5. Apparatus according to claim 4 wherein said rotatable drive memberincludes a pin and the lower support ring includes a L-shaped slotpositioned in the lower portion of such ring, said hollow tube beingconnected to said rotatable drive member by said pin which extends intosaid L-shaped slot.

6. Apparatus according to claim 1 including an indexing pointer whereinsaid rotatable annular disk is calibrated to indicate the relativeposition of said conveyor means, such indication being given by theposition of the calibrated disk relative to said indexing pointer.

References Cited in the file of this patent UNITED STATES PATENTS1,505,441 Smith Aug. 19, 1924 2,695,729 Hornish Nov. 30, 1954 2,967,152Matsch Jan. 3, 1961

1. IN AN APPARATUS FOR STORING AND DISPENSING LOW-TEMPERATURE MATERIALSCOMPRISING A DOUBLE-WALLED VACUUMINSULATED STORAGE CONTAINER HAVING ANACCESS PORT IN THE TOP WALL THEREOF COMMUNICATING WITH THE CONTAINERINTERIOR, A COVEYOR MEANS POSITIONED IN SUCH INTERIOR, TRANSMISSIONMEANS LOCATED WITHIN SAID INTERIOR AND ROTATABLY COMMUNICATING WITH SAIDCONVEYOR MEANS, A ROTATABLE DRIVE MEMBER POSITIONED IN SAID INTERIOR ANDOPERABLY ATTACHED TO SAID TRANSMISSION MEANS, AND A REMOVABLE LOWHEATCONDUCTIVE MEANS FOR CLOSING SAID ACCESS PORT THEREBY SUBSTANTIALLYCOMPLETELY SEALING SAID INTERIOR FROM THE EFFECTS OF AMBINET HEAT, THEIMPROVEMENT COMPRISING A ROTATABLE TRANSMISSION ACTUATING MEANS FITTEDWITHIN SAID ACCESS PORT SUCH THAT OPERATION OF SUCH ACTUATING MEANS DOESNOT EFFECT THE ACCESSIBLITY OF SAID INTERIOR; SAID ACTUATING MEANSCOMPRISING A TUBE WHICH IS CONNECTED TO SAID TRANSMISSION MEANS BY SAIDROTATABLE DRIVE MEMBER, AND A ROTATABLE DISK INTEGRALLY ATTACHED TO THEUPPER PORTION OF SAID ACTUATING MEANS SUCH THAT UPON ROTATING SUCH DISK,SAID ACUTATING MEANS ACTUATES SAID TRANSMISSION MEANS THEREBY OPERATINGSAID CONVEYOR MEANS.